Airflow system for bagless vacuum cleaner

ABSTRACT

A bagless vacuum cleaner ( 10 ) includes a nozzle assembly ( 16 ) having a suction nozzle for picking up dirt and debris from a surface to be cleaned and a canister assembly ( 18 ) including a cavity ( 32 ). A dust collection assembly ( 12 ) is received and held in that cavity ( 32 ). The dust collection assembly ( 12 ) includes a filtering subassembly ( 100 ) and a dust container ( 102 ). The dust container ( 102 ) has an open top ( 104 ), a bottom wall ( 106 ), a first cylindrical sidewall ( 108 ), an inlet ( 110 ), and a downwardly directed outlet ( 112 ) extending through the bottom wall. An airstream conduit is provided for conveying a vacuum airstream between the suction nozzle and the inlet. A suction fan ( 34 ) and suction fan drive motor ( 35 ) carried on either the nozzle assembly ( 16 ) or the canister assembly ( 18 ) generates the vacuum airstream for drawing dirt and debris through the suction nozzle, the airstream conduit and the dust container ( 102 ).

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/237,832, filed Oct. 3, 2000.

TECHNICAL FIELD

[0002] The present invention relates generally to the vacuum cleanerart, and, more particularly, to a bagless vacuum cleaner incorporating anovel air flow system.

BACKGROUND OF THE INVENTION

[0003] A recent consumer products trend has resulted in a rapid increasein the popularity of bagless upright vacuum cleaners. Such vacuumcleaners generally incorporate a washable and rigid dust container orcup for collecting intermediate and larger particles of dirt and debrisand a second, upstream corrugated paper, porous foam or like filter orfilter cartridge for collecting smaller dirt and dust particles. Theintermediate and larger particles of dirt and debris are collected inthe dust container or cup usually by establishing a vortex airstreamtherein which allows the heavier particles to be separated from theairstream and collected in the bottom of the container or cup.Generally, the container or cup is made from transparent or translucentmaterial so that the operator may observe the “cyclonic” cleaningaction. This seems to add significantly to the customer satisfactionwith the product. Of course, the transparent or translucent container orcup also allows the operator to confirm when the cup or container isnearing capacity. At that time the vacuum cleaner may be switched offand the cup or container removed for emptying into a garbage can orother appropriate dirt receptacle.

[0004] While many available designs exist for bagless vacuum cleaners itshould be appreciated that further improvements in design includingimprovements in air flow so as to provide more cleaning power and moreefficient operation are still desired. The present invention meets thisgoal.

SUMMARY OF THE INVENTION

[0005] In accordance with the purposes of the present invention asdescribed herein, an improved bagless vacuum cleaner is provided. Thebagless vacuum cleaner includes a nozzle assembly having a suctionnozzle for picking up dirt and debris from a surface to be cleaned and acanister assembly including a cavity. The bagless vacuum cleaner alsoincludes a dust collection assembly. That dust collection assemblyincludes a filtering subassembly and a dust container. The dustcontainer has an open top, a bottom wall and a first cylindricalsidewall. The container also includes an inlet that in at least oneembodiment is directed tangentially with respect to the firstcylindrical sidewall in order to establish a vortex airstream to allowefficient cleaning action. Still further, the dust container includes adownwardly directed outlet which extends through the bottom wall of thecontainer. The bagless dust collection assembly is received and held inthe cavity in the canister assembly.

[0006] The bagless vacuum cleaner further includes an airstream conduitfor conveying a vacuum airstream between the suction nozzle and theinlet. Additionally, a suction fan and suction fan drive motor iscarried on either the nozzle assembly or the canister assembly. Thesuction fan and cooperating suction fan drive motor function to generatethe vacuum airstream for drawing dirt and debris through the suctionnozzle, the airstream conduit and the dust container.

[0007] More specifically describing the invention, the dust containerincludes a second cylindrical sidewall concentrically received withinthe first cylindrical sidewall so that at least a portion of the dustcontainer is annular. This second cylindrical sidewall defines anexhaust pathway which is provided in fluid communication with theoutlet.

[0008] The filtering subassembly includes a main body and a cooperatingcover defining a primary filter cavity. A primary filter is positionedin the primary filter cavity. The primary filter divides the primaryfilter cavity into an intake chamber and a discharge chamber. Theprimary filter may take the form of an annular corrugated filter madefrom paper or other natural and/or synthetic fiber material appropriatefor the intended purpose.

[0009] The main body of the filter subassembly includes a downwardlydepending exhaust conduit which provides fluid communication between thedischarge chamber and the exhaust pathway leading to the outlet.Additionally, the main body includes a first conical wall around theintake chamber.

[0010] A prefilter is carried on the main body. The prefilter extendsconcentrically around the exhaust conduit but is spaced therefrom so asto form an intake channel between the prefilter and the exhaust conduit.The intake channel is provided in fluid communication with the intakechamber. The prefilter may take the form of a cylindrical open-endedscreen.

[0011] An air current guide may be carried on the main body adjacent theprefilter. The air current guide extends between the prefilter and thesecond cylindrical sidewall. The air current guide includes a disc-likeseparator and at least one downwardly depending air current guide vane.

[0012] Once fully assembled a first gap having a width W₁ is formedbetween the prefilter and the first cylindrical sidewall of the dustcontainer. Further, the inlet includes a diameter D₁. The diameter D₁ is≦the width W₁. In a typical embodiment, diameter D₁ is between about 30mm-35 mm and the width W₁ is between about 34 mm-36 mm. Additionally, asecond gap having a width W₂ between about 12 mm-16 mm is providedbetween an outer edge of the separator and the first cylindricalsidewall.

[0013] The vacuum cleaner also includes a filter clicker carried on thecover of the filtering subassembly. The filter clicker includes acleaning element having at least one projecting lug and an actuator forrotating the cleaning element relative to the primary filter. Theprimary filter preferably includes a frame for supporting the corrugatedfilter material. A series of projecting tabs extend from the frame. Theprojecting lug on the cleaning element engages the series of projectingtabs on the frame vibrating the frame and filter material held by theframe and thereby cleaning dirt from the primary filter when theactuator is manually manipulated.

[0014] In accordance with yet another aspect of the present invention amethod is provided for directing airflow through a bagless vacuumcleaner wherein that vacuum cleaner includes a primary filter and a dustcontainer having an inlet and an outlet. The method includes the stepsof directing the airflow from the inlet around the dust container,drawing the airflow upwardly through the primary filter and dischargingthe airflow downwardly through the outlet by passing the airflow througha discharge conduit extending through a bottom wall of the dustcontainer.

[0015] In addition, the present invention may be broadly described asrelating to a novel bagless upright vacuum cleaner also providingbeltless operation. The bagless upright vacuum cleaner includes a nozzleassembly having a suction nozzle for picking up dirt and debris from asurface to be cleaned and a canister assembly pivotally mounted to thenozzle assembly and including a control handle. The upright vacuumcleaner also includes a washable dust container providing a baglessmeans for collecting dirt and debris cleaned from the surface.Additionally, an agitator is held in the nozzle assembly. A beltlessagitator drive motor carried on the nozzle assembly or the canisterassembly is provided for driving the agitator and lifting dirt anddebris from the surface. A suction fan and beltless suction fan drivemotor carried on the nozzle assembly or the canister assembly generatesa vacuum airstream for drawing dirt and debris through the suctionnozzle into the dust container.

[0016] Still other objects of the present invention will become readilyapparent to those skilled in this art from the following descriptionwherein there is shown and described a preferred embodiment of thisinvention simply by way of illustration of one of the modes best suitedto carry out the invention. As it will be realized, the invention iscapable of other different embodiments and its several details arecapable of modification in various, obvious aspects all withoutdeparting from the invention. Accordingly, the drawings and descriptionswill be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING

[0017] The accompanying drawing incorporated in and forming a part ofthis specification, illustrates several aspects of the presentinvention, and together with the description serves to explain theprinciples of the invention. In the drawing:

[0018]FIG. 1 is a perspective view of a vacuum cleaner constructed inaccordance with the teachings of the present invention;

[0019]FIG. 2 is a cross-sectional view through the nozzle assembly ofthe vacuum cleaner showing the agitator and agitator drive arrangement.

[0020]FIG. 2a is a detailed cross-sectional view through the agitator;

[0021]FIG. 3 is an exploded perspective view of the dust collectionassembly incorporated into the vacuum cleaner of the present invention;

[0022]FIG. 4 is a cross-sectional view of the dust collection assembly;and

[0023]FIGS. 5a and 5 b are cutaway, cross-sectional views through thecanister assembly showing the latch handle in the unlatched and latchedpositions respectively.

[0024] Reference will now be made in detail to the present preferredembodiment of the invention, an example of which is illustrated in theaccompanying drawing.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Reference is now made to FIG. 1 showing the vacuum cleaner 10 ofthe present invention. It should be appreciated that while an uprightvacuum cleaner 10 is illustrated, embodiments of the present inventionalso include canister vacuum cleaners incorporating a dust collectionassembly 12 of the nature that will be described in detail below.

[0026] The upright vacuum cleaner 10 illustrated includes a nozzleassembly 16 and a canister assembly 18. The canister assembly 18 furtherincludes a control handle 20 and a hand grip 22. The hand grip 22carries a control switch 24 for turning the vacuum cleaner on and off.Of course, electrical power is supplied to the vacuum cleaner 10 from astandard electrical wall outlet through a cord (not shown).

[0027] At the lower portion of the canister assembly 18, rear wheels 26are provided to support the weight of the vacuum cleaner 10. A secondset of wheels 27 allow the operator to raise and lower the nozzleassembly 16 through selective manipulation of the height adjustmentswitch 28. Such a height adjustment mechanism is well known in the artand is exemplified, for example, by the arrangement incorporated intothe Kenmore Progressive Vacuum Cleaner presently in the marketplace. Toallow for convenient storage of the vacuum cleaner 10, a foot latch (notshown) functions to lock the canister assembly 18 in an upright positionas shown in FIG. 1. When the foot latch is released, the canisterassembly 18 may be pivoted relative to the nozzle assembly l6 as thevacuum cleaner 10 is manipulated to-and-fro to clean the floor.

[0028] The canister assembly 18 includes a cavity 32 adapted to receiveand hold the dust collection assembly 12. Additionally, the canisterassembly 18 carries a suction fan 34 and suction fan drive motor 35.Together, the suction fan 34 and its cooperating drive motor 35 functionto generate a vacuum airstream for drawing dirt and debris from thesurface to be cleaned. While the suction fan 34 and suction fan drivemotor 35 are illustrated as being carried on the canister assembly 18,it should be appreciated that they could likewise be carried on thenozzle assembly 16 if desired.

[0029] The nozzle assembly 16 includes a nozzle and agitator cavity 36that houses a rotating agitator brush 38. The agitator brush 38 shown isrotatably driven by a motor 40 and cooperating gear drive 42 housedwithin the agitator and described in greater detail below (see FIGS. 2and 2a). In the illustrated vacuum cleaner 10, the scrubbing action ofthe rotary agitator brush 38 and the negative air pressure created bythe suction fan 34 and drive motor 35 cooperate to brush and beat dirtand dust from the nap of the carpet being cleaned and then draw the dirtand dust laden air from the agitator cavity 36 to the dust collectionassembly 12. Specifically, the dirt and dust laden air passes seriallythrough a suction inlet and hose and/or an integrally molded conduit inthe nozzle assembly 16 and/or canister assembly 18 as is known in theart. Next, it is delivered into the cyclonic dust collection assembly 12(described in greater detail below) which serves to trap the suspendeddirt, dust and other particles inside while allowing the now clean airto pass freely through to the suction fan 34, a final filtrationcartridge 48 and ultimately to the environment through the exhaust port50.

[0030] Reference is now made to FIGS. 2 and 2a which show the mountingof the agitator motor 40 and associated gear drive 42 in the agitator 38in detail. As shown, the agitator 38 is mounted for rotation relative tothe nozzle assembly 16. Specifically, a first end of the agitator 38includes an end cap 52 which is supported on bearings 54 on a stub shaft55 held in mounting block 56 keyed into slot 58 in the side of thenozzle assembly 16. An end cap 60 at the opposite end of the agitator 38is supported on bearings 62 mounted on the housing 64 of the motor 40.As should be appreciated, the motor 40 is fixed to the nozzle assembly16 by means of the mounting block 66 fixed to the motor housing 64 andkeyed in the slot 68 in the side of the nozzle assembly.

[0031] The motor 40 drives a shaft 70 including gear teeth 72. The driveshaft 70 extends through a bearing 74 held in the hub 76 of theplanetary gear set carrier 78. In the most preferred embodiment a fan 80is keyed or otherwise secured to the distal end of the drive shaft 70.

[0032] The planetary gear set carrier 78 includes three stub shafts 82that each carry a planetary gear 84. Each of the planetary gears 84include teeth that mesh with the gear teeth 72 of the drive shaft 70.Additionally, the planetary gears 82 mesh with the teeth of an annulargear 86 that is fixed to the agitator motor housing 64 by pin or othermeans. Thus, it should be appreciated that as the drive shaft 70 isdriven by the motor 40, the planetary gears 84 are driven around theannular gear 86, thereby causing the planetary gear set carrier 78 torotate.

[0033] Planetary gear set carrier 78 also includes a drive ring 88 andassociated rubber drive boot 87 which includes a series of spacedchannels 89 that receive and engage axial ribs 91 projecting inwardlyradially from the inner wall of the agitator 38. Thus, the rotation ofthe planetary gear set carrier 78 is transmitted by the drive ring 88and drive boot 87 directly to and causes like rotation of the agitator38. The rubber drive boot 87 provides the necessary damping to insurethe smooth transmission of power to the agitator 38. Simultaneously withthe rotation of the planetary gear set carrier 78 and agitator 38, thedrive shaft 70 also drives the fan 80 at a ratio of between 4-1 to 10-1and most preferably 6-1 with respect to the agitator 38. The resultingrapid rotation of the fan 80 helps to move air through the agitator 38and ensure proper cooling of the agitator motor 40 during its operation.

[0034] The dust collection assembly 12 will now be described in detail.The dust collection assembly 12 includes a filtering subassemblygenerally designated by reference numeral 100 and a dust container 102.Dust container 102 includes an open top 104, a bottom wall 106 and afirst cylindrical sidewall 108. An inlet 110 is shown directedtangentially with respect to the cylindrical sidewall 108. In thisorientation, the inlet 110 promotes the formation of a vortex airstreamas described in greater detail below. It should be appreciated, however,that substantially any other inlet orientation could be utilized and theformation of a vortex airstream is not critical to the presentinvention.

[0035] A downwardly directed outlet 112 extends through the bottom wall106. A second or inner cylindrical sidewall 114 is concentricallyreceived within the first cylindrical sidewall 108 so that at least aportion of the dust container 102 is annular. As best shown in FIG. 3,the second cylindrical sidewall 114 defines an exhaust passageway 116provided in fluid communication with the outlet 112.

[0036] The filtering subassembly 100 includes a main body 118 and acooperating cover 120. Together the main body 118 and cooperating cover120 define a primary filter cavity 122. A primary filter 124 ispositioned in the primary filter cavity 122 and divides that cavity intoan intake chamber 126 and a discharge chamber 128. In one embodiment,the primary filter 124 is an annular corrugated filter made from paperor other natural and/or synthetic fiber material with each of thecorrugations held by a plastic frame 130. That frame 130 includes aseries of upwardly projecting tabs 132 radially arranged about theprimary filter 124.

[0037] The main body 118 includes a downwardly depending exhaust conduit134 providing fluid communication between the discharge chamber 128 andthe exhaust pathway 116 leading to the outlet 112. As also shown themain body 118 includes a frustoconical wall 136 defining the peripheralmargin of the intake chamber 126.

[0038] A prefilter 138 is carried on the main body 118 below thefrustoconical wall 136. The prefilter 138 is shown as comprising acylindrical open-ended screen which extends concentrically around theexhaust conduit 134 so as to form an intake channel 140 between theprefilter 138 and the exhaust conduit 134. Of course, other materialssuch as a porous plastic could be used for the prefilter. The intakechannel 140 is provided in fluid communication with the intake chamber126 through spaced openings 142 in the base 144 of the main body 118.

[0039] As further shown in FIGS. 3 and 4, an air current guide,generally designated by reference numeral 146 is carried by the mainbody 118 adjacent the prefilter 138. The air current guide 146 extendsbetween the prefilter 138 and the second cylindrical sidewall 114 of thedust container 102. As shown the air current guide 146 includes a discshaped separator 148 and one or more downwardly depending air currentguide vanes 150. Each air current guide vane is canted inwardly between0°-30° from the vertical toward the second cylindrical sidewall 114. Thefunction of the separator 148 and guide vane 150 will be described ingreater detail below.

[0040] In operation, dirt and debris lifted by the agitator brush 38 anddrawn through the suction inlet and hose passes through the inlet 110.Inlet 110 directs the air to tangentially flow in a cyclonic path (noteaction arrows A in FIG. 3) around the dust container 102. Specifically,the air first flows around a prefilter 138 with the heavier debrisfalling under the force of gravity toward the bottom of the dustcontainer 102. The air current guide vane 150 helps maintain smooth,uninterrupted and unturbulent cyclonic flow in order to maximizecleaning action. Further, the inward cant of the guide vane causes dirtand debris entrained in the airstream A to move toward the center of thedust container 102. This effectively compacts the dirt and debrisallowing the dust container to fill to a higher capacity. The largestand heaviest of the dirt and debris entrained in the vacuum airstreamdelivered into the dust container 102 through the inlet 110 settles tothe bottom wall 106 of the dust container.

[0041] The vacuum airstream now devoid of the relatively larger andheavier dust, debris and particles is drawn through the prefilter screen138 into the intake channel 140. The screen includes pores having adiameter of between substantially 40 μm and 300 μm. Relativelyintermediate size dust, dirt and debris too light to settle to thebottom of the dust container 102 but too large to pass through theprefilter screen 138 is removed from the vacuum airstream by theprefilter screen. There this material collects and gradually accumulatesinto a heavier mass which will eventually fall under the force ofgravity onto the separator 148 where it will be displaced by the movingairstream and drop down into the bottom of the dust container 102.

[0042] As best shown by action arrow B, the vacuum airstream movingthrough the prefilter screen 138 into the intake channel 140 is thendrawn through one of the apertures 142 in the main body 118 into theintake chamber 126. From the intake chamber 126 the vacuum airstream isdrawn upwardly through the primary filter 124 which removessubstantially all of the remaining fine dust from the airstream. Nextthe vacuum airstream is drawn into the discharge chamber 128. From therethe vacuum airstream is redirected downwardly through the exhaustconduit 134 and then the exhaust passageway 116 to the outlet 112. Fromthere the airstream passes through a foam or sponge rubber filter pad152 carried at the bottom wall of the cavity 32 in the canister assembly18. That filter pad 152 covers the inlet to a passageway (not shown)leading to the suction fan 34. From there the vacuum airstream isexhausted over the suction fan drive motor 35 to provide cooling and isdelivered through a sound muffling passageway to the final filtrationcartridge 48 and then it is exhausted through the exhaust port 50.

[0043] The flow of the vacuum airstream is carefully shaped andcontrolled throughout its passage through the vacuum cleaner 10 in orderto ensure the highest possible cleaning efficiency. Toward this end afirst gap 154 having a width W₁ of between about 34 mm and 36 mm isprovided between the prefilter screen 138 and the first cylindricalsidewall 108. The inlet 110 is provided with a diameter D₁ of betweenabout 30 mm and 35 mm. In the most preferred embodiment diameter D₁≦thewidth W₁.

[0044] Additionally, a second gap 156 having a width W₂ between about 12mm and 16 mm is provided between an outer edge of the separator 148 andthe first cylindrical sidewall 108. The width W₂ of the gap 156 must becarefully controlled as it allows the separator 148 to concentrate thevacuum airflow from the inlet 110 in the area of the prefilter screen138 away from the dirt and debris collecting in the bottom of the dustcontainer 102. This is done while simultaneously maintaining asufficiently large gap 156 to allow the free passage of the larger,heavier dirt and dust particles entrained in the airstream into thelower portion of the dust container 102 where they can be collected.

[0045] During vacuuming, the dust container 102 will gradually fill withdirt and debris which will also collect on the prefilter screen 138.Further, fine dust particles will be collected on the primary filter124. By forming the dust container 102 and the cover 120 of thefiltering subassembly 100 from transparent or translucent plasticmaterial it is possible to visually monitor and inspect the condition ofthe dust container and primary filter 124 during vacuuming. Followingvacuuming or as otherwise necessary it is easy to dispose of this dirtand debris. Specifically, the vacuum cleaner is turned off and the dustcollection assembly 12 is removed from the cavity 32 in the canisterassembly 18. This may be done by lifting and releasing the latch handle158 (the operation of which is described in greater detail below) or bysimply pulling the dust collection assembly 12 from its nested positionif no latch is provided. The latch handle 158 is pivotally connected tothe cover 120 and serves as a simple and convenient means of handlingthe dust collection assembly 12.

[0046] A filter clicker, generally designated by reference numeral 160,allows easy cleaning of the primary filter 124. More specifically, thefilter clicker 160 includes a revolving cleaning element 162 shown witha pair of projecting lugs 164. An exposed actuator 166 is carried on thetop of the cover 120. The actuator 166 includes a hub 168 which projectsthrough an opening in the cover 120 and engages in a cooperating socketprovided in the cleaning element 162. By manually rotating the actuator166, the cleaning element 162 is likewise rotated and the projectinglugs 164 engage with each of the series of projecting tabs 132 on theframe 130 of the primary filter 124. As the projecting lugs 164resiliently snap past the projecting tabs 132, the corrugated filtermaterial is vibrated shaking the fine dust and dirt particles from theprimary filter 124. Since the projecting tabs 132 are provided aroundthe outer margin of the frame, greater vibration is produced for bettercleaning action. These dust and dirt particles then drop under the forceof gravity and slide down the frustoconical sidewall 136 of the mainbody, pass through the apertures 142 and drop down into the bottom 170of the intake channel 140 where they are captured.

[0047] The cover 120 is then removed from the dust container 102 bytwisting. When separated the filtering subassembly 100 including themain body 118, cover 120, prefilter screen 138 and air current guide 146stay together as a unit. As the filtering subassembly 100 and the dustcontainer 102 are separated, the bottom 170 of the intake channel 140opens and the fine dirt and debris that is collected there from thecleaning of the primary filter 124 falls under the force of gravity intothe bottom of the dust container 102. Similarly, any relatively lightdirt and debris remaining on the prefilter screen 138 or the upper ledgeof the separator 148 falls easily to the bottom of the container withminor shaking of the filtering subassembly 100 during its removal fromthe container. The dirt and debris is then dumped from the container 102into a garbage receptacle. The filtering subassembly 100 is thenrejoined with the dust container 102 by twisting the cover 120 onto thethreaded upper end of the dust container 102. The entire dust collectionassembly 12 is then repositioned in the cavity 32 in the canisterassembly 18 with the inlet 110 in communication with a coupling 47 whichis in communication with the hose or other conduit leading to the nozzleand the outlet 112 which is in communication with the port 113 leadingto the suction fan 34.

[0048] As best shown in FIGS. 3, 5a and 5 b, the latch handle 158 ispivotally connected to the cover 120 by opposed stub shafts 200 receivedin cooperating opposed apertures in the cover. Springs 201 bias thelatch handle to the latched position resting flat against the cover 120.When disengaged or unlatched, the latch handle 158 may be utilized inthe manner of a handle of a pail to conveniently hold and manipulate thedust collection assembly 12. As the dust collection assembly 12 is beingsecured in the cavity 32 the latch handle 158 is utilized to provide apositive connection.

[0049] More specifically, the latch handle 158 includes a pair of spacedcams 202 that engage a cooperating lip or shoulder 204 on the canisterassembly 18. Thus, as the latch handle 158 is pressed downwardly towardthe cover 120, the cams 202 engage the shoulder 204 thereby forcing thedust collection assembly 12 rearwardly and downwardly. This dual actionfirmly seats the inlet 110 in the coupling 47 and the outlet 112 in theport 113 leading to the suction fan 34. As a result, a good seal isprovided at each connection, vacuum pressure losses are avoided and peakoperating efficiency of the suction fan is insured.

[0050] Under certain circumstances, such as after extended heavy dutyservice, it may become necessary to access the primary filter 124. Thisis relatively easily accomplished. More particularly, the main body 118and the cover 120 of the filtering subassembly 100 are connectedtogether by means of the upstanding mounting flange 170 on the main bodywhich provides either a threaded or a fiction fit in the cooperatinggroove 172 of the cover 120. Accordingly, the cover 120 may be pulled orunscrewed from the main body 118 to open the primary filter cavity 122.The primary filter 124 is then replaced with a new filter. The cover 120is then repositioned on the main body 118 by inserting the mountingflange 170 in the cooperating groove 172 and completing thereconnection.

[0051] The foregoing description of the preferred embodiment of thisinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise form disclosed. Obvious modifications orvariations are possible in light of the above teachings. For example, aback light 180 could be provided behind the dust collection assembly 12in the cavity 32 of the canister assembly 18 to visually enhancemonitoring of the airflow and/or dirt level in the dust container 102.The vacuum cleaner 10 could also include a bypass valve (not shown) inthe airstream conduit upstream from the inlet 110. The valve could bespring loaded to permit only high velocity air flow into the dustcontainer 102. If desired, a performance indicator of the type presentlyfound on the Kenmore Model 38912 upright vacuum cleaner could beprovided in the airstream conduit to give a true indication of vacuumcleaner performance. Further, while the vacuum cleaner is described withan agitator drive motor held in the agitator, the drive motor could bepositioned outside of the agitator in either the nozzle assembly or thecanister assembly in any manner desired. Additionally, while the dustcollection assembly 12 is illustrated as being carried in a cavity 32 inthe canister assembly 18, it should be appreciated that it could also bemounted in a cavity or by means of some other structure on the nozzleassembly 16 as well.

[0052] The embodiment was chosen and described to provide the bestillustration of the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art toutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth to which they are fairly, legally and equitably entitled.

What is claimed: 1.) a bagless vacuum cleaner, comprising: a nozzleassembly including a suction nozzle for picking up dirt and debris froma surface to be cleaned; a canister assembly; a dust collection assemblyincluding a filtering subassembly and a dust container, said dustcontainer having an open top, a bottom wall, a first cylindricalsidewall, an inlet, and a downwardly directed outlet extending throughsaid bottom wall, said dust collection assembly being received and heldon one of said nozzle assembly and said canister assembly; an airstreamconduit for conveying a vacuum airstream between said suction nozzle andsaid inlet; and a suction fan and suction fan drive motor carried on oneof said nozzle assembly and said canister assembly for generating saidvacuum airstream for drawing dirt and debris through said suctionnozzle, said airstream conduit and said dust container. 2.) The vacuumcleaner of claim 1 wherein said dust container includes a secondcylindrical sidewall concentrically received within said firstcylindrical sidewall so that at least a portion of said dust containeris annular. 3.) The vacuum cleaner of claim 2, wherein said secondcylindrical sidewall defines an exhaust pathway in fluid communicationwith said outlet. 4.) The vacuum cleaner of claim 3, wherein saidfiltering subassembly includes a main body and a cooperating coverdefining a primary filter cavity. 5.) The vacuum cleaner of claim 4,further including a primary filter positioned in said primary filtercavity and dividing said primary filter cavity into an intake chamberand a discharge chamber. 6.) The vacuum cleaner of claim 5, wherein saidprimary filter is an annular corrugated material filter. 7.) The vacuumcleaner of claim 5, wherein said main body includes a downwardlydepending exhaust conduit providing fluid communication between saiddischarge chamber and said exhaust pathway leading to said outlet. 8.)The vacuum cleaner of claim 7, wherein said main body includes afrustoconical wall around said intake chamber. 9.) The vacuum cleaner ofclaim 8, further including a prefilter carried on said main body, saidprefilter extending concentrically around said exhaust conduit so as toform an intake channel between said prefilter and said exhaust conduit,said intake channel being in fluid communication with said intakechamber. 10.) The vacuum cleaner of claim 9, wherein said prefilter is acylindrical, open ended screen or porous material. 11.) The vacuumcleaner of claim 9, further including an air current guide carried onsaid main body and extending between said prefilter and said secondcylindrical sidewall, said air current guide being canted inwardlybetween about 0°-30° from the vertical. 12.) The vacuum cleaner of claim11, wherein said air current guide includes a separator and at least onedownwardly depending air current guide vane. 13.) The vacuum cleaner ofclaim 6, further including a filter clicker carried on said cover, saidfilter clicker including a cleaning element having at least oneprojecting lug and an actuator for rotating said cleaning elementrelative to said primary filter and wherein said primary filter includesa support frame having a series of projecting tabs, said projecting lugengaging said series of projecting tabs to vibrate and clean dirt fromsaid primary filter. 14.) The vacuum cleaner of claim 12, wherein afirst gap having a width W₁ is formed between said prefilter and saidfirst cylindrical sidewall, and said inlet includes a diameter D₁ wherediameter D₁≦W₁. 15.) The vacuum cleaner of claim 14, wherein saiddiameter D₁ is between about 30 mm-35 mm and width W₁ is between about34 mm-36 mm. 16.) The vacuum cleaner of claim 12, wherein a second gaphaving a width W₂ between about 12 mm-16 mm is provided between an outeredge of said separator and said first cylindrical sidewall. 17.) Thevacuum cleaner of claim 1, wherein said inlet is directed tangentiallywith respect to said first cylindrical sidewall. 18.) A method ofdirecting air flow through a vacuum cleaner including a dust containerhaving an inlet and an outlet and a primary filter, comprising:directing said air flow from said inlet into said dust container;drawing said air flow upwardly through said primary filter; anddischarging said air flow downwardly through said outlet by passing saidair flow through a discharge conduit extending through a bottom wall ofsaid dust container. 19.) An upright vacuum cleaner, comprising a nozzleassembly including a suction nozzle for picking up dirt and debris froma surface to be cleaned; a canister assembly pivotally mounted to saidnozzle assembly and including a control handle; a washable, bagless dustcontainer for collecting dirt and debris cleaned from said surfacecarried on one of said nozzle assembly and said canister assembly; anagitator held in said nozzle assembly; a beltless agitator drive motorcarried on one of said nozzle assembly and said canister assembly fordriving said agitator and lifting dirt and debris from said surface; anda suction fan and beltless suction fan drive motor carried on one ofsaid nozzle assembly and said canister assembly for generating a vacuumairstream for drawing dirt and debris through said suction nozzle intosaid dust container.